Optical measurement systems are often embedded in other systems, such as mechanical and electrical systems, with which they cooperate to provide an intended function or subfunction. The optical systems are thus subject to a variety of disturbances arising from the equipment in which they are embedded or with which they are cooperative. In order to make high quality measurements, such as for the optical measurement system aboard a spacecraft, the bandwidth of the measurement must be, as a rule of thumb, on the order of twenty times the bandwidth of the disturbances to which the optical system is subjected. For some typical high accuracy applications, the bandwidth of the disturbance may be approximately 150 hertz, so that the measurement bandwidth must be on the order of 3,000 hertz or more. Optical measurement systems must in these and other instances be operative at the corresponding bandwidth to avoid and reduce disturbance contamination.
In some optical systems, one or more elements are monitored to provide an intended control or other action. The elements may be of the optical system or of the one or more systems in which the optical system is embedded. It therefore becomes essential that a multiple spot processing capability capable of simultaneously monitoring multiple system components and processing the data representative of the components is provided.
A real-time processing system capability, where measurements are made as often as critical events occur, and control action appropriate to the change in conditions is executed, is also desireable in some instances. Furthermore, it is often necessary to be able to run in a mode other than a real-time mode to be able to accomplish special requirements that the system may dictate, such as the ability to selectably run one or more computationally intensive control algorithms. Optical measurement systems should therefore have as well a multiple mode processing capability.